The present invention relates generally to a dispenser for applying a correction film to a substrate surface. More particularly, the invention relates to a reel assembly for a correction tape dispenser that utilizes a viscous clutch for maintaining proper tension in the correction tape.
A number of devices are known that are designed to apply a correction film to a surface. The correction film includes an adhesive surface that adheres to the surface of a substrate and is generally provided on a carrier tape. The correction film is typically adhered to the surface of a substrate by applying pressure against the tape at the surface. Examples of previously known devices include those described in U.S. Pat. Nos. 5,310,437, 5,942,036, and 6,062,286. Correction tape of this type is also utilized in typewriters. An example of a correction tape cartridge that is utilized in a typewriter is described in U.S. Pat. No. 4,350,453.
Correction tape dispensers take on a variety of forms and are generally formed of a housing having a supply reel or spool containing the correction film and carrier tape, and a second take-up spool or reel for accepting the tape after usage. The tape is fed over an applicator member, which extends from the housing. The device is held in the hand of a user who applies pressure to the applicator member on a surface at a pressure sufficient to transfer the film from the tape to the surface.
Dispensers are designed so that movement of the tape over a substrate surface causes the tape to unwind from the supply reel while maintaining a tension on the tape so that rotation of the supply reel causes the take-up reel to wind and accept the spent tape. It is desirable to maintain a tension on the tape so that it can be wound on the take-up reel, but the tension must not be so great as to break the tape. In order to maintain the proper tension, a clutch is normally provided to connect the take-up reel to the supply reel. A clutch allows for slippage during application while maintaining the proper tension in the tape to ensure effective feeding of the tape over the applicator member.
Applicator devices may have a single reel design, such as that disclosed in U.S. Pat. No. 5,310,437, or a double reel design, such as disclosed in U.S. Pat. No. 6,062,286. A single reel dispenser is one in which the supply reel and take-up reel are aligned along a common axis while a double reel dispenser typically includes two different axes.
U.S. Pat. No. 5,310,437 describes a device where the supply reel has a diameter that is smaller than the diameter of the take-up reel. The take-up reel includes a plurality of knurls and an arcuate leaf spring that seats on the spent tape as the tape passes over the knurls. The tape does not wind around the take-up reel. Instead, the tape passes over the take-up reel and may be stored or cut off. Due to the difference between the diameters of the take-up reel and supply reel, the tape is moved at a greater linear rate over the knurls of the take-up reel than it is being unwound from the outer surface of the supply reel. When this occurs, slippage takes place between the knurls and the leaf spring, maintaining tension in the tape throughout its travel from the supply reel to the take-up reel. The leaf spring in combination with the knurls creates a form of slip clutch between the take-up reel and the supply reel.
U.S. Pat. No. 6,062,286 describes a device with two reels disposed on different shafts that includes a clutch for synchronizing the supply speed and take-up speed. The supply reel is mounted on a support shaft formed integrally with the inner side of the case body. The take-up reel recovers the spent tape and is positioned on a separate support shaft. The clutch mechanism includes engaging protrusions and an engaging support member. The engaging protrusions function as frictional engaging members.
It is desirable to provide an improved clutch mechanism which is reliable, simple, and inexpensive to manufacture.
The present invention is directed toward a reel assembly for use in a tape dispenser, to a cartridge for housing a reel assembly, and to a tape dispenser, preferably a correction tape dispenser. The reel assembly of one embodiment of the present invention includes a supply reel, a take-up reel in mating association with the supply reel, and a viscous material positioned between the supply reel and the take-up reel. The viscous material serves as a clutch between the supply reel and the take-up reel and provides controlled drag between the supply reel and the take-up reel in order to properly tension a tape being dispensed from the tape dispenser.
The take-up reel includes a mating portion for mating with a mating portion of the supply reel. The viscous material is provided between the mating portion of the supply reel and the mating portion of the take-up reel. The area between the mating portions of the supply and take-up reels may be substantially disk shaped. The viscous material may be a silicone fluid. Alternatively, the viscous material may include a mixture of silicone gum and a silicone fluid.
A seal may be provided between the take-up reel and the supply reel and may be configured and dimensioned to retain the viscous fluid between the take-up reel and the supply reel. The seal may extend outwardly from and be integral with the wall of the take-up reel. Alternatively, the seal may be an independent member positioned between the supply reel and the take-up reel in the vicinity of the viscous material.
The reel assembly may include a mechanism for increasing the friction between the supply reel and the take-up reel. In one embodiment of the invention, at least one rib may be positioned on at least one of the supply reel or the take-up reel. The rib is for association with the viscous material. The rib may be a concentric rib or a radial rib. Alternatively, or in combination therewith, a surface treatment may be provided on at least one of the supply reel or the take-up reel. The surface treatment is also in association with the viscous material.
Dimensional controls may be provided on the reel assembly. The dimensional controls ensure that an area is maintained between at least part of the supply reel and at least part of the take-up reel for holding the viscous material. The dimensional controls may include a cylindrical wall of the supply reel that abuts a surface of the take-up reel.
The supply reel includes a tape carrier surface for holding a roll of correction tape. The take-up reel may also include a tape carrier surface for accepting spent correction tape. Both tape carrier surfaces have a diameter, and the supply reel tape carrier surface may have a diameter that is smaller than the diameter of the take-up reel tape carrier surface. The supply reel has an axis and the take-up reel has an axis. In one embodiment, the axis of the take-up reel is not coaxial with the axis of the supply reel.
The reel assembly may also include a knob associated with at least one of the supply reel or the take-up reel for rotating the supply reel or the take-up reel relative to the other reel in order to free the supply reel from the take-up reel.
One embodiment of the present invention also relates to a cartridge for housing a reel assembly of a tape dispenser, preferably a correction tape dispenser. The cartridge includes a reel assembly and a body for housing the reel assembly. The body has at least one opening defined therein for the entrance and exit of a tape. The body may include a top shell portion and a bottom shell portion, with the top and bottom shell portions in mating association with one another. The body is configured and dimensioned for insertion into a tape dispenser, preferably a correction tape dispenser.
In another embodiment, the present invention also relates to a tape dispenser that includes a body, a reel assembly, a dispenser tip, and tape. The body forms the outside of the tape dispenser. The tape dispenser is preferably a correction tape dispenser. The reel assembly is positioned within the body and has a viscous clutch. The dispenser tip is positioned within the body and has a portion that extends from the body. The tape is disposed on the reel assembly and extends from the reel assembly around the dispenser tip and back to the reel assembly. The reel assembly may be mounted on a boss that extends from the body of the tape dispenser.
The reel assembly includes a take-up reel and a supply reel. The supply reel houses a roll of unused (correction) tape and the take-up reel houses the spent (correction) tape. The take-up reel includes a mating portion for mating with a mating portion of the supply reel, the viscous clutch positioned between the mating portion of the take-up reel and the mating portion of the supply reel. The area defined between the mating portion of the supply reel and the mating portion of the take-up reel may be substantially disk shaped.
The viscous clutch includes a viscous material that is provided between the mating portion of the take-up reel and the mating portion of the supply reel. The viscous material provides controlled drag between the supply reel and the take-up reel in order to properly tension the (correction) tape being dispensed from the supply reel to the take-up reel. The viscous material may be a silicone substance. In one embodiment, the viscous material is a mixture of at least silicone gum and silicone fluid.
A surface treatment may be provided on at least one of the mating portions of the supply reel or the take-up reel. The surface treatment may be in intimate contact with the viscous material. In addition, a knob may be associated with the reel assembly for manually rotating at least one of the take-up reel or the supply reel. The knob is accessible from outside the body.